Today, I bring you a classic puzzle produced by ThinkFun, the Spin-Out, which was invented by William Keister in 1970 (patented in 1972). Considered to be a modern version of the Chinese Rings, which are believed to date back over 2000 years ago, the Spin-Out was first introduced to the public in 1987, when the company was still known as Binary Arts, later changing its name to ThinkFun in 2003.

The Spin-Out (or SpinOut) is a sequential movement puzzle comprised by seven knobs attached to a sliding platform. The knobs can be maneuvered into one of two possible states, either horizontal or vertical. The initial configuration of the puzzle has all knobs in the vertical position, and the goal is simply put them all in the horizontal position, forming a straight line, so the platform can slide out. This sounds simple, but it has more to it than just spinning knobs up and down.

Throughout the years there have been a few other versions of the Spin-Out, including one with elephants (see interactive version here). The first version released by Binary Arts had red knobs and the cover was a little simpler. The newer version, revamped by the rebranded ThinkFun in 2005 has a more modern look, with blue knobs and you can see their logo at the bottom. Which one do you think looks better? - I prefer the blue one.

The solution of the puzzle is very linear, as it follows a simple binary logic called Gray code. The mechanism is built so that only one knob at a time can be moved. For any knob you want to move, the one immediately to its right has to be in the vertical position and any subsequent ones have to be in the horizontal position. The solution has a minimum of 85 moves and while it uses a simple method, it requires the utmost concentration or you will lose track of your train of thought. This really happened to me a few times - I had to gather my thoughts and analyse where I was in the sequence and what the next move should be.

When you understand the logic behind the puzzle, it's not that difficult. What's difficult, as I pointed above, is to keep concentrated and not lose the sequence. When you're able to solve it back and forth (all knobs horizontal and all knobs vertical) you can try to beat your own times and see how fast you can do it. See this video of a kid solving it under 30s. After mastering this puzzle you can try other similar ones that also use the Gray code to be solved. The Brain is another great puzzle that I recommend.

Markus Götz designed a much harder version of the Spin-Out called Crazy Elephant Dance, which uses a ternary system. Instead of two states, the elephants can be maneuvered into three possible positions. There's a nice Java applet in the page that lets you play the puzzle with different levels of difficulty. Can you solve it in the harder level?

Closing Comments:

Back when ThinkFun was Binary Arts, their puzzles were much more interesting. The Spin-Out, a simple and yet brilliant concept is proof that a puzzle doesn't need fancy looks to be fun and enjoyable. It's a great puzzle to keep your brain healthy and sharp, while providing a very satisfying and rewarding experience.

Availability: Sloyd.fi, in Finland, currently stocks the new blue version of the Spin-Out for just €12. Shipping worldwide is available.

Links:

Analysis of the Spin-Out puzzle by Jaap Scherphuis